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In message 7CC93B1ACC5743A3B5536DBF798B7016@vectron.com, "Bob Camp" writes:

Has anybody ever studied if mono-isotopic quartz in the first place ?

I pressume that would be a requirement in order to link it to the
atomic weight unit ?

--
Poul-Henning Kamp      | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG        | TCP/IP since RFC 956
FreeBSD committer      | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

Poul-Henning Kamp wrote:

The current intention is to accurately measure Silicon 28 single crystal
spheres and use the result to refine the value for Avogadros number and
thus allow a redefinition of the kilogram using Avogadros number and the
mass of an atom:

http://www.ptb.de/en/aktuelles/archiv/presseinfos/pi2011/pitext/pi110127.html

Essentially one would then measure mass of such standards by counting atoms.

Bruce

Hi

The objective of the Avogadro Project seems to be getting to an accuracy of
0.03 ppm from a current level of ~ 10X that. The suggestion in the paper is
that a quartz resonator could be monitored for change to a much tighter
level than that.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Bruce Griffiths
Sent: Tuesday, January 22, 2013 2:39 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] One Kg Quartz Resonator

Poul-Henning Kamp wrote:

writes:

SI

The current intention is to accurately measure Silicon 28 single crystal
spheres and use the result to refine the value for Avogadros number and
thus allow a redefinition of the kilogram using Avogadros number and the
mass of an atom:

http://www.ptb.de/en/aktuelles/archiv/presseinfos/pi2011/pitext/pi110127.htm
l

Essentially one would then measure mass of such standards by counting atoms.

Bruce

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I'm absolutely sure that TVB has one :-)
Don

"Neither the voice of authority nor the weight of reason and argument
are as significant as experiment, for thence comes quiet to the mind."
De Erroribus Medicorum, R. Bacon, 13th century.
"If you don't know what it is, don't poke it."
Ghost in the Shell

Dr. Don Latham AJ7LL
Six Mile Systems LLP
17850 Six Mile Road
POB 134
Huson, MT, 59846
VOX 406-626-4304
www.lightningforensics.com
www.sixmilesystems.com

But can the number and type of atoms in such a standard be counted?
Otherwise its not a primary standard.

Bruce

Bob Camp wrote:

Hi

The primary standard of mass today is simply an arbitrary lump of metal
sitting in Paris. There's no atom counting involved. There also is a Watt
Balance project trying another approach to rectifying the issue. The only
one that seems to be Time Nutty is the quartz resonator proposal.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Bruce Griffiths
Sent: Tuesday, January 22, 2013 3:30 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] One Kg Quartz Resonator

But can the number and type of atoms in such a standard be counted?
Otherwise its not a primary standard.

Bruce

Bob Camp wrote:

of

is

the

http://www.ptb.de/en/aktuelles/archiv/presseinfos/pi2011/pitext/pi110127.htm

atoms.

https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

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In message 50FEF6DB.4020404@xtra.co.nz, Bruce Griffiths writes:

Yes.

If you arrange them into a perfect sphere, you can measure the
crystal-grid spacing very precisely with x-rays, and the diameter
even more precisely with lasers.

Interestingly, this experiment may also become the first time we
ever needed to know PI better than 355/113 outside abstract
mathematics.

My friends in metrology all bet on the watt-balance supplying the
new mass definition, rather than the quartz-ball, simply because they
are so much easier to construct.  The isotope-separation is really
a killer.

--
Poul-Henning Kamp      | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG        | TCP/IP since RFC 956
FreeBSD committer      | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

The isotope-separation is really

How about crystal boundaries? Certainly to count atoms, and to resonate
properly, should be a single crystal. In that case, not a sphere but
hexagonal...Maybe a 1 kg sc-cut?

--
"Neither the voice of authority nor the weight of reason and argument
are as significant as experiment, for thence comes quiet to the mind."
De Erroribus Medicorum, R. Bacon, 13th century.
"If you don't know what it is, don't poke it."
Ghost in the Shell

Dr. Don Latham AJ7LL
Six Mile Systems LLP
17850 Six Mile Road
POB 134
Huson, MT, 59846
VOX 406-626-4304
www.lightningforensics.com
www.sixmilesystems.com

Yes, Don, those old quartz bars are rare and amazing:

http://leapsecond.com/museum/gr676b-50kc/
http://leapsecond.com/museum/gr1190a/

The inside joke is that recently Don gave me a new one, also GenRad, that I hope to photograph and measure soon.

Thanks,
/tvb (iPhone4)

On Jan 22, 2013, at 3:04 PM, "Don Latham" djl@montana.com wrote:

Hi

I think we are getting two things crossed up here.

The sphere approach is pure silicon. It's called Avogadro and it's quite far along. It does not involve Time Nutty stuff.

The quartz resonator is simply an idea at this point. There does not appear to be a defined shape for the resonator yet. It's performance is very dependent on a number of Time Nut sort of things.

The silicon sphere intends to create a true primary standard by counting atoms. The quartz resonator intends to replace one artifact (the current standard lump of metal) with another artifact (a great big lump of quartz).

There is a third approach (the Watt balance) that as yet has not gotten tangled. It's trying to create a true standard by way of electromagnetics.

Bob

On Jan 22, 2013, at 4:19 PM, "Don Latham" djl@montana.com wrote:

Hi

In addition to the two you show in the pictures, there was another one. It lived in a pine box oven. The oven and associated "stuff" took up at least a full rack. I really wish I'd bought the only one I've ever seen…

Bob

On Jan 22, 2013, at 5:19 PM, Tom Van Baak (lab) tvb@leapsecond.com wrote:

Il 2013-01-22 23:19 Tom Van Baak (lab) ha scritto:

What is the function of the (metal?) disc
plates near the two ends of the rods?
Their position seem to be trimmable.

Thank,
Fabio.

Hi

As with the one kg resonator, you need to mount the bar somehow. The idea is generally to suspend the resonator at a point that least affects the resonance (a dead spot). With a large bar, making it manually adjustable is practical. Not so much with a smaller part.

Bob

On Jan 22, 2013, at 7:14 PM, Fabio Eboli fabioeb@quipo.it wrote:

I also have two of the crystals. The discs are used to adjust the phase of
the acoustic feedback to the resonator ends.

John  WA4WDL

From: "Fabio Eboli" FabioEb@quipo.it
Sent: Tuesday, January 22, 2013 7:14 PM
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Subject: Re: [time-nuts] One Kg Quartz Resonator

On 1/22/2013 3:30 PM, Bruce Griffiths wrote:

Can you have a Cs under zero acceleration and at zero temperature, the
only conditions for which the second is defined? Since most metric units
are derived from the definition of the second, are any "primary
standards," in your opinion?

On 01/23/2013 02:32 AM, Mike S wrote:

Isn't it defined for zero sea-level, that is standard acceleration?

Besides, as you put two standards in the same lab at the same level,
they should give the same values. Some of the art is to compensate for
various effects, so accurately model, estimate and compensate goes into
the tricks of trade today.

The standard shifts as better methods of realizing them occurs, the kg
has been taking a long time to shift from the original lump of metal.

Cheers,
Magnus

Il 2013-01-23 01:54 jmfranke ha scritto:

Thanks Bob and John, I gave a superficial read to one of the patents,
as I understand the patent says that the plates are there to give
predictable acoustic reflections (yes I know I should read before
posting questions :)  )
Bob the dead spot mounting is interesting (are they called nodal
points,
or I'm mistaking terminology?).
The metallization on the 50kc rod is on top and bottom plates, while
the 100kc is "swapped", one electrode on top on one half and bottom
on the other half rod. The suspension is also different, the
50kc is supended in the middle while the 100kc is suspended
in two points. How are supposed to vibrate these bars? Will they
inflect
along the long axis? Or elongate? Or a mix of different motions?

Thanks.
Fabio.

Hi

You want to mount the crystal at a point that is not moving (much) while the crystal is in resonance. For a normal AT, that's out at the edge. For most bar cuts, yes you mount it at a node. Without knowing the mode that the bar is resonating in, it's a bit hard to guess where the nodes will be. Just looking at the bar, you wouldn't guess that the end points would be nodes...

Bob

On Jan 23, 2013, at 5:07 AM, Fabio Eboli fabioeb@quipo.it wrote:

Il 2013-01-23 13:39 Bob Camp ha scritto:

Sorry Bob I didnt understand last part.
You say that the end faces are nodes that move very little?
Or that it's hard to tell the way they move?
I asked that because reading the patent, I understand
that the plates are trimmed to stay near the rod and
not touching it, to give costant air reflection behaviour.
And talks about supersonic movement of the air, so I
was wondering why that was only a problem on end faces
and not on other "long" faces of the rod.

Thanks,
Fabio.